It's not easy being green - 1971 TC

[Cheguava]

Starting with the restoration of my currently derelict, originally Pistachio / Lime Green TC, now the last but 1 owner, who had it from 1980-2004 had visited to see it and offer advice. Also spoke to the owner from 2004-2024, who bought it, then bought an American TCS and left this one under a sheet for 20 years, which explains why mine how has Federal rear light units at least.

Fair to say the first bits of stripping down have had more down than upsides. I'll either need complete UK light units or UK lenses and modify the units to suit them.  Side repeaters are knacked and won't come out (Dr Dremel is going to visit them) and the alternator is seized, which is understandable, but I can't see a reference to it online - Delco DN460? **EDIT** Have now found the DN460, also fitted to TR6 and some Spitfires, at £300+ will work on freeing mine first.

There was good news though. The football sized wasp nest in the rear corner had been abandoned by its occupants. Yay!  Off for a few days while I plan the campaign to strip and separate the body from the chassis, using the fine guide on this site.  Will post progress, forwards and backwards, on this thread.

Does anyone know what type of ignition key would be required for a 71 TC? There's a number inside the lock but I'm unsure of the key type, it's a Waso lock but I can't narrow it down further.

[BDA]

Congratulations on your first step in you journey!! I'm really glad the wasps (hornets?) left before you took delivery!

Our own My S1 found a place to buy keys in the UK,  https://www.keytrader.co.uk/. I don't know if they know which blanks you need but you can give them a call. The usual suspects in the UK probably sell key blanks too (SJ Sports Cars, Kelvedon Lotus, Lotus Supplies, etc.). The Lotus archivist may be able to find which number keys your car used and Lotus might be able to help with the particular key numbers (to reproduce your original keys). Here's his address: AGraham at lotuscars dot com.

Good luck!

[Cheguava]

Thanks BDA. I've already contacted Andy at Lotus to pass him the car's details for their register, worth asking the question about key numbers, but I'll wait until I get the door locks out as I understand those numbers are possibly on the barrels.

Cheers, Jeff

[EuropaTC]

alternator is seized, which is understandable, but I can't see a reference to it online - Delco DN460? **EDIT** Have now found the DN460, also fitted to TR6 and some Spitfires, at £300+ will work on freeing mine first.

I can't help on the keys but maybe on the alternator. IIRC some folks have had their originals overhauled so that is one option. I decided not to and when mine failed I simply fitted a Lucas 17ACR instead and modified the wiring. That's a very tight fit but the 16ACR is slightly smaller and in hindsight would have been the better option. The 17ACR lasted for a while until I saw a more modern Lucas A127 for £55 on Ebay so I got one of those to replace the 17ACR. The A127 is a very good fit for the car and comes in several outputs, some of which are probably too great for the car's wiring should you ever achieve the maximum charge rate.

This is how it went together;

http://www.martley.plus.com/lotusland2016/europa/16europa03.html 

(it's a very old and quaint website, but it's about the details not the coding !)

Brian

[Cheguava]

Hi Brian, that is really helpful info on the alternator - I'm spoilt for choice now! 

Thanks for the link to your website, which is fantastic - no idea what you mean about Yorkshire Pennine weather though.    Many happy hours of reading ahead - looks like you've done all the stuff I'm going to have to go through.  Massive help.

Best wishes,
Jeff

[GavinT]

..... some of which are probably too great for the car's wiring should you ever achieve the maximum charge rate.

That's something I've wondered about.
I don't know the gauge or amps rating of the 'big' brown wire, but is it much different to normal cars running a 70 amp alternator?
At a glance, it doesn't seem so but I'm no expert.
Enquiring minds and all that...

[EuropaTC]

That's something I've wondered about.
I don't know the gauge or amps rating of the 'big' brown wire, but is it much different to normal cars running a 70 amp alternator?
At a glance, it doesn't seem so but I'm no expert.
Enquiring minds and all that...

When I fitted the A127 it comes in several ratings (55/65/70/?? IIRC), the higher ones don't use the spade terminal plug but are stud connections with, from the photos I saw, fairly chunky wiring. There are plenty of cable guides on the internet but most of them stopped at 50amps. I did find one supplier that gave a 70amp rating and that was massive, almost 8mm and I don't think I've ever seen that in a car before.

https://www.autoelectricsupplies.co.uk/p/standard-cable

To be honest it's mostly above my head. I could never grasp electronics, if I can't see it, touch it or hit it, then it's black magic.  After reading about wire lengths/diameters/voltage drops I guessed the big problems were voltage drops or the wire getting overheated.  With the ammeter in the dash and what's probably a longer cable run than most cars I figured Lotus had probably sized their cable  on a 30amp rating (5mm on that chart).  But as I'd never seen anywhere near 30amps before I just put the A127 in and watched the ammeter.  It works and after running for what's now several years  (2016)  there's no visible problems on the brown wires, so technically correct or not, it seems to work ok.

[jbcollier]

I would not run 70 amps through the stock wiring and amp gauge.  If you go 70 amps, bin the ammeter and just join all its wires together (not the wires for the bulb), fit a voltmeter, and run a short, fat wire from the alt to the battery.

[RonPNW]

Having just finished re-wiring, I have few comments.
If you want a historically correct restoration ignore the rest of this post and just repair what you have.

I wanted to take advantage of modern technology in any way that did not change the character and general look of the car.

On my 70 S2 some wire was internally damaged and over 50% of the connections were corroded or failed. I removed the amp meter (not really necessary if you sort out the electrical system, I replaced it with an air / fuel meter and added an idiot light). Also remove the high current coil wire that runs through the tach (there are several posts, on this site, on how to do this. It dramatically reduces the electrical noise in the car allowing a radio to work properly).

I sized my wire by using the length and resistance of the wire (many tables on line) to find the wire gauge that results in .5V of voltage drop at max current.  Voltage drop = Max Current X Total Resistance. Total resistance includes the wire to the battery, wire to ground, and any switches or connections on the way. A good clean flat connector or switch will be less than .05 ohms. Good solder connections are 0 ohms.

If you remove the ammeter the only high current connections / lines go to the radiator fan, cabin fan, headlights and starter. I added relays to front area so the cabin switches just turn on the relays.

I replaced the alternator with a mini-denso 70A ( https://www.ebay.com/itm/151571437369. ) .Smaller, lighter, more current, internally regulated. Some fab for the mounting is needed. Link to dimensions  https://www.amazon.com/DENSO-EXCITING-ALTERNATOR-MOUNT-1-WIRE/dp/B00DMS4YIG.   

But ..... I have heard you can simply buy a new wiring harness and move on.

Ron